JP2007001339A - Internal combustion engine waste heat recovery plant in propulsive device of vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine waste heat recovery plant capable of improving general energy efficiency of a propulsive system. <P>SOLUTION: This internal combustion engine waste heat recovery plant of a vessel 1 having the composite propulsive system 3 of a main machine 9 and electric propulsion is characteristically furnished with a turbine 19 for generator driving to drive a generator 21, a boiler 17 to form superheated steam, a high pressure steam forming means 23 to form high pressure steam by collecting a heating value from exhaust gas of the main machine 9 and a low pressure steam forming means 25 to form low pressure steam, a superheated steam supplying line 67 to introduce the superheated steam to an inlet of the turbine 19 for generator driving, a high pressure steam line 69 to introduce the high pressure steam to an upper stage side air mixing stage of the turbine 19 for generator driving, a low pressure steam line 71 to introduce the low pressure steam to a lower stage side air mixing stage of the turbine 19 for generator driving and a control part to control to reversely decrease and increase supplying quantity of the superheated steam line 67 when high pressure steam quantity and low pressure steam quantity increases and decreases. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an internal combustion engine waste heat recovery plant for a ship having a propulsion system in which a main engine in which an internal combustion engine is directly connected to a propeller and an electric propulsion device, and a ship using the same.

2. Description of the Related Art In recent years, large ships equipped with diesel main engines have used electric propulsion as a backup or auxiliary propulsion means in order to increase output, improve maneuverability, and ensure redundancy.
Conventionally, the electric power for this electric propulsion is supplied by shaft power generation of a diesel main engine or a plurality of separately provided diesel generators as disclosed in Patent Document 1, for example.

JP-T-2004-530588 (paragraphs [0020] to [0038] and FIGS. 1 to 2)

  However, what is shown in Patent Document 1 is generated by an auxiliary generator driven by a diesel engine, and does not consider using exhaust gas from the main engine. Generally, the exhaust gas from the main engine contains heat that can be used as power, and using this is important in improving the overall energy efficiency.

  In view of the above problems, an object of the present invention is to provide an internal combustion engine waste heat recovery plant for a ship that can improve the overall energy efficiency of a propulsion system, and a ship using the same.

In order to solve the above problems, the present invention employs the following means.
That is, a ship internal combustion engine waste heat recovery plant according to the present invention drives a generator that supplies electric power for electric propulsion in a ship having a propulsion system that combines a main engine and electric propulsion by the internal combustion engine, A turbine for driving a generator having a plurality of air-fuel stages in a portion, a boiler that generates superheated steam, high-pressure steam generation means that recovers heat from the exhaust gas of the internal combustion engine and generates high-pressure steam, and the high-pressure steam generation On the downstream side of the means, low pressure steam generating means for recovering heat from the exhaust gas of the internal combustion engine to generate low pressure steam, and superheated steam supply for introducing the superheated steam generated by the boiler into the inlet of the generator driving turbine A high-pressure steam line for introducing the high-pressure steam generated by the high-pressure steam generating means into the upper mixed stage of the generator driving turbine, and the low-pressure steam generating means When the amount of steam in the low-pressure steam line for introducing the low-pressure steam into the lower mixed gas stage of the generator driving turbine and the steam pressure in the high-pressure steam line and the low-pressure steam line increases or decreases, the supply amount of the superheated steam line decreases on the contrary. And a control means for adjusting to increase.

As described above, the generator driving turbine that drives the generator that supplies electric propulsion power includes high-pressure steam and low-pressure generated by using the exhaust gas of the internal combustion engine as a heat source in addition to the superheated steam generated by the boiler. Since it is also driven by steam, the amount of heat discarded from the internal combustion engine (main engine) can be fully utilized, and the energy efficiency of the propulsion system can be improved.
In addition, the control means adjusts so that the amount of superheated steam supplied to the superheated steam line is decreased when the amount of steam in the high pressure steam line and the low pressure steam line increases or decreases. Will be used preferentially. As a result, the high-pressure steam and low-pressure steam that are generated by recovering the amount of heat from the exhaust gas of the internal combustion engine are effectively utilized by the generator driving turbine even if the amount of steam increases or decreases according to the operating conditions of the internal combustion engine. Therefore, the energy efficiency of the propulsion system can be further improved.
The high-pressure steam generating means and the low-pressure steam generating means are appropriately supplied with water, but it is preferable to use a water supply line to the boiler. In this way, water supply facilities do not overlap, so that the structure of the propulsion system can be simplified and manufactured at low cost.

  In the internal combustion engine waste heat recovery plant for a ship according to the present invention, the high-pressure steam generating means includes a high-pressure evaporator installed in an exhaust gas passage of the internal combustion engine, and high-pressure steam-water separation for supplying water and separating high-pressure steam And a high-pressure circulation line that connects the high-pressure evaporator and the high-pressure steam separator to circulate a fluid, and the low-pressure steam generating means is downstream of the high-pressure evaporator in an exhaust gas passage of an internal combustion engine. A low-pressure evaporator installed in the apparatus, a low-pressure steam separator that feeds water and separates low-pressure steam, and a low-pressure circulation line that connects the low-pressure evaporator and the low-pressure steam separator to circulate a fluid. And at least the low-pressure steam-water separator is installed in a water supply line to the boiler.

  Thus, since at least the low pressure steam-water separator is installed in the water supply line to the boiler, gas components can be separated from the water supplied to the boiler. Moreover, the feed water to a boiler can be heated. For this reason, the feed water heater provided with the steam-water separation function installed in the feed water line of a low-pressure steam-water separator boiler can be omitted.

  In the internal combustion engine waste heat recovery plant for a ship according to the present invention, the high-pressure steam generating means includes a high-pressure evaporator installed in an exhaust gas passage of the internal combustion engine, and high-pressure steam-water separation for supplying water and separating high-pressure steam And a high-pressure circulation line that connects the high-pressure evaporator and the high-pressure steam separator to circulate a fluid, and the low-pressure steam generating means is downstream of the high-pressure evaporator in an exhaust gas passage of an internal combustion engine. A low-pressure evaporator installed in the apparatus, a low-pressure steam separator that feeds water and separates low-pressure steam, and a low-pressure circulation line that circulates fluid by connecting the low-pressure evaporator and the low-pressure steam separator. And the high-pressure steam separator is a steam drum of the boiler.

  Thus, since the high-pressure steam separator is a boiler steam drum, there is no need to provide a separate high-pressure steam separator, and the manufacturing cost can be reduced accordingly.

  Further, in the ship internal combustion engine waste heat recovery plant according to the present invention, the boiler branches from the main flue and does not pass through a part of the water pipe, and a superheater installed in the bypass flue And a flow path adjusting means for adjusting a ratio of combustion gas passing through the main flue and the bypass flue.

Since the combustion gas passing through the bypass flue does not pass through a part of the water pipe, the combustion gas is maintained at a higher temperature than the combustion gas passing through the main flue. The steam passing through the superheater is efficiently converted into superheated steam by this relatively high-temperature combustion gas, and sent to the turbine for driving the generator.
When the amount of high-pressure steam and low-pressure steam varies, the required amount of superheated steam varies. The amount of steam per unit time passing through the superheater changes in accordance with this variation, and the superheated steam temperature changes. In this case, since the amount of combustion gas passing through the bypass flue can be adjusted by the flow path adjusting means and the amount of superheat to the steam passing through the superheater can be adjusted, the superheated steam temperature can be easily adjusted (predetermined) Temperature).

  In the internal combustion engine waste heat recovery plant for a ship according to the present invention, the fuel oil supply line of the internal combustion engine is provided with a separation means for separating the solid content from the liquid fuel containing the solid content. The waste oil separated from the liquid fuel is supplied to a liquid fuel supply line of the boiler.

In this way, the waste oil separated by the separating means provided in the fuel oil supply line of the internal combustion engine is supplied to the liquid fuel supply line of the boiler, and fuel is generated in the boiler that is not greatly affected by the fuel properties compared to the internal combustion engine. Therefore, the energy of the fuel can be used effectively.
Further, even if the waste oil rate is increased in order to improve the cleanliness of the fuel oil, since the influence on the overall fuel consumption is small, the degree of cleaning in the separating means can be improved. For this reason, by supplying clean fuel oil to the internal combustion engine, the durability of the internal combustion engine can be improved and the life can be extended.
In general, diesel oil, heavy oil, residual oil or the like is used as the liquid fuel for the marine internal combustion engine. These contain impurities such as solids (sludge), and in particular, heavy oil produced from residues in petroleum refining processes and residue oils contain a large amount of sludge.

A ship according to the present invention includes the internal combustion engine waste heat recovery plant according to any one of claims 1 to 5.
Thus, since the internal combustion engine waste heat recovery plant that fully utilizes the amount of heat discarded from the internal combustion engine is used, the energy efficiency of the propulsion system can be improved.

  According to the present invention, a generator driving turbine for driving a generator for supplying electric power for electric propulsion includes high pressure steam generated using exhaust gas from an internal combustion engine as a heat source in addition to superheated steam generated by a boiler. Since it is also driven by low-pressure steam, the amount of heat discarded from the internal combustion engine can be fully utilized, and the energy efficiency of the propulsion system can be improved.

Hereinafter, the ship 1 concerning one Embodiment of this invention is demonstrated using FIGS.
FIG. 1 is a block diagram showing an overall schematic configuration of the propulsion system 3. In FIG. 1, solid lines connecting the members indicate steam and water supply pipelines, broken lines indicate signal lines such as detection signals and control signals, and alternate long and short dash lines indicate power lines.
A main propeller 5 and a pod propeller 7 are provided as propulsion means at the lower rear part of the ship 1.
The main propeller 5 is configured to be rotationally driven by a main machine 9 connected via a propeller shaft. For example, a heat-efficient two-stroke diesel engine (internal combustion engine) is used as the main engine 9.
The pod propulsion unit 7 includes a pod body 11 attached to the lower portion of the rudder, a pod propeller 13 attached to the front portion of the pod body 11, and a pod motor 15 that drives the pod propeller 13 inside the pod body 11. Is provided.

The propulsion system 3 includes a main propeller 5, a main engine 9, a pod propeller 7, a boiler 17, a generator driving turbine 19, a generator 21, a high-pressure steam generation unit 23, and a low-pressure steam generation unit 25. And are provided.
As the boiler 17, for example, a natural circulation water tube boiler is used. The boiler 17 includes a furnace 24 having a substantially box shape, a combustion device 26 provided on the top of the furnace 24, an evaporation tube group 27, a steam drum 29 provided above the evaporation tube group 27, and evaporation. A water drum 31 provided below the tube group 27, a main flue 33, and a bypass flue 35 are provided.
The main flue 33 is formed such that the combustion gas passes from the outlet portion of the furnace 24 through the substantially lower half of the evaporator tube group 27 and makes a U-turn and passes upward through the approximately upper half of the evaporator tube group 27.

The bypass flue 35 is branched from the main flue 33 on the upstream side of the main flue 33 toward the upper half of the evaporation pipe group 27 and is formed to be directed upward. The combustion gas passing through the bypass flue 35 does not pass through substantially the upper half of the evaporator tube group 27, so that the combustion gas is maintained at a higher temperature than that of the main flue by the amount not absorbed by the combustion gas.
The main flue 33 and the bypass flue 35 are joined at the upper side. A flue damper (flow path adjusting means) 37 is provided at this joining position. One end of the flue damper 37 is swingably attached to a lower meeting portion of the main flue 33 and the bypass flue 35, and is configured to adjust the cross-sectional area of each flue by swinging. Has been.
A heat exchange core 39 is mounted on the downstream side of the flue damper 37 of the bypass flue 35. The heat exchange core 39 is provided with a superheater 41 and a economizer 43 from the upstream side.

The generator driving turbine 19 is a multistage type, and is provided with an air-mixing stage that can introduce steam into the intermediate positions M and L. The position M is located on the upper side of the position L.
The generator 21 is connected to the rotating shaft of the generator driving turbine 19 and is driven by the generator driving turbine 19 to generate electric power.

The high-pressure steam generating means 23 is connected to the high-pressure evaporator 45, the high-pressure steam / water separator 47 that separates steam and water, and the high-pressure circulation that circulates the fluid by connecting the high-pressure evaporator 45 and the high-pressure steam / water separator 47. A line 49 and a high-pressure circulation pump 51 that is disposed in the high-pressure circulation line 49 and circulates a fluid are provided.
The high-pressure evaporator 45 is positioned inside the high-pressure core 44 installed in the exhaust gas passage 53 of the main machine 9 and is configured to exchange heat with the exhaust gas of the main machine 9.
In the present embodiment, the high-pressure steam-water separator 47 is provided independently, but the steam drum 29 may be used as the high-pressure steam-water separator.
The exhaust gas passage 53 is provided with an exhaust gas bypass 55 branched at a branch position S on the downstream side of the high-pressure evaporator 45. An exhaust gas damper 56 is provided at the branch position S. The exhaust gas damper 56 distributes the exhaust gas flow path to either the exhaust gas bypass 55 or the exhaust gas passage 53.

The low-pressure steam generating means 25 is connected to a low-pressure evaporator 57, a low-pressure steam / water separator 59 that separates steam and water, and a low-pressure circulation circuit that circulates fluid by connecting the low-pressure evaporator 57 and the low-pressure steam / water separator 59 to each other. A line 61 and a low-pressure circulation pump 63 that is disposed in the low-pressure circulation line 61 and circulates the fluid are provided.
The low-pressure evaporator 57 is positioned inside the low-pressure core 46 installed on the downstream side of the branch position S in the exhaust gas passage 53 of the main machine 9 and is configured to exchange heat with the exhaust gas of the main machine 9.
The high-pressure evaporator 45 and the low-pressure evaporator 57 are arranged separately in the high-pressure core 44 and the low-pressure core 46, but may be arranged in the same core.

The steam drum 29 is connected to a boiler pressure steam line 65 that supplies high-pressure saturated steam into the ship. Connected to the upstream side of the boiler pressure steam line 65 is a superheated steam line 67 that passes through the superheater 41 and is connected to the inlet of the turbine 19 for driving the generator.
A high-pressure steam line 69 connects the high-pressure steam / water separator 47 and the position M of the generator-drive turbine 19 in order to introduce the high-pressure steam generated by the high-pressure steam / water separator 47 into the generator-drive turbine 19. It is provided as follows.
In order to introduce the low-pressure steam generated by the low-pressure steam-water separator 59 into the generator-drive turbine 19, the low-pressure steam line 71 connects the low-pressure steam-water separator 59 and the position L of the generator-drive turbine 19. It is provided as follows.

A boiler pressure steam condensate line 75 connected to the atmospheric pressure condenser 73 is branched at a position X downstream of the branch point of the superheated steam line 67 in the boiler pressure steam line 65.
Further, at position X, a steam supply line 77 connected to the low-pressure steam separator 59 is branched.
A low pressure condensate line 79 connected to the atmospheric pressure condenser 73 is branched at a position Y on the downstream side of the low pressure steam line 71.
Further, a low-pressure steam supply line 81 that supplies low-pressure saturated steam into the ship is branched at a position Z upstream of the low-pressure steam line 71.
A communication line 83 that connects a position V, which is an intermediate portion of the steam supply line 77, and an intermediate portion of the high-pressure steam line 69 is provided.

The outlet steam of the generator driving turbine 19 is introduced into the suction condenser 85 and condensed.
A water supply line 87 of the boiler 17 connects the suction condenser 85, the atmospheric pressure condenser 73, and the low pressure steam / water separator 59, and also passes through the economizer 43 and the low pressure steam / water separator 59 and steam. A drum 29 is formed to be connected.
In order to supply condensate from each condenser to the low-pressure steam separator 59, an atmospheric pressure condensate pump 89 is provided on the supply line 87 at the atmospheric pressure condenser 73 side, and suction is provided at the suction condenser 85 side. A condensate pump 91 is provided.
A water supply pump 93 for supplying water from the low pressure steam / water separator 59 to the steam drum 29 is provided on the downstream side of the low pressure steam / water separator 59 in the feed water line 87.

Next, control means for controlling the operation of the propulsion system 3 will be described with reference to FIG.
FIG. 3 is a block diagram showing a control flow of the steam valve used in the propulsion system 3. In FIG. 3, the pressure is higher as it is positioned higher as indicated by the long arrow on the left side. FIG. 3 is an arrangement of communication relationships focusing on the pressure relationship, and the specific positional relationship is shown in FIG.
The boiler pressure steam condensate line 75 is provided with a boiler pressure dump valve 97. The boiler pressure dump valve 97 is an electronic regulating valve, and has a high pressure corresponding to the measured value of the boiler pressure manometer 99 that measures the pressure of the upstream boiler pressure steam condensate line 75 by the boiler pressure controller 101. If so, the opening is adjusted to be larger.

The steam supply line 77 is provided with a high-pressure steam supply valve 103 on the position X side across the position V, and a low-pressure steam supply valve 105 on the low-pressure steam / water separator 59 side.
The low pressure condensate line 79 is provided with a low pressure dump valve 107.
Both the low-pressure steam supply valve 105 and the low-pressure dump valve 107 are electronic control valves, and the opening degree is adjusted by the low-pressure controller 109 corresponding to the measured value of the low-pressure pressure gauge 111 that measures the pressure of the low-pressure steam supply line 81. It is configured as follows.
The low-pressure controller 109 has a function F1 that represents the relationship between the pressure and the opening of the low-pressure steam supply line 81 as shown in FIG. 4, and thereby the openings of the low-pressure steam supply valve 105 and the low-pressure dump valve 107 are adjusted. Configured to adjust.

That is, the opening degree K1 of the low-pressure dump valve 107 is the minimum opening degree up to the pressure P1, and when the pressure K1 rises above the pressure P1, the opening degree increases proportionally, reaches the pressure P2, reaches the maximum opening degree, and the pressure thereafter. The maximum opening is maintained even if it rises.
On the other hand, the opening degree K2 of the low-pressure steam supply valve 105 is the maximum opening degree up to the pressure P3. The minimum opening is maintained even if the rises.
This function F1 is an example, and is changed in response to a change in the situation. However, as a tendency, when the measured value of the low-pressure pressure gauge 111 increases, the low-pressure steam supply valve 105 tends to close. On the other hand, the low pressure dump valve 107 is operated in the opening direction.
The high-pressure steam supply valve 103 is an electronic adjustment valve, and is configured to open when the measured value of the high-pressure manometer 115 that measures the pressure of the steam supply line 77 on the position V side by the high-pressure controller 113 exceeds a predetermined value. Yes.

A main steam valve 117 is provided on the superheated steam line 67 on the generator driving turbine 19 side. The main steam valve 117 is an electronic adjustment valve, and the opening degree is adjusted by a governor 119. An instruction command D indicating required power is input to the governor 119 from an operation control device (not shown), and an opening degree is set corresponding to the instruction command D.
On the other hand, the opening information of the high pressure steam supply valve 103 and the low pressure dump valve 107 is input to the governor 119. Based on these pieces of information, the instruction command D is such that the larger the opening degree of the high-pressure steam supply valve 103 is, the more the opening degree of the main steam valve 117 is opened by the instruction instruction D, while the larger the opening degree of the low-pressure dump valve 107 is. Therefore, the opening degree of the main steam valve 117 is corrected in the closing direction.

A high pressure check valve 121 and a high pressure on-off valve 123 are provided on the generator drive turbine 19 side of the high pressure steam line 69.
A low pressure check valve 125 and a low pressure on-off valve 127 are provided between the generator driving turbine 19 of the low pressure steam line 71 and the position Y.
The high pressure check valve 121 and the low pressure check valve 125 prevent steam from flowing back from the generator driving turbine 19 to the high pressure steam line 69 or the low pressure steam line 71, respectively.
The high-pressure on-off valve 123 and the low-pressure on-off valve 127 open and close the high-pressure steam line 69 or the low-pressure steam line 71, respectively.

The superheated steam line 67 is provided with a superheated thermometer 129 for measuring the temperature of the superheated steam. The superheat temperature controller 131 adjusts the position of the flue damper 37 according to the measured value of the superheat thermometer 129.
That is, if the superheated steam temperature measured by the superheat thermometer 129 is lower than the predetermined value, the superheat temperature controller 131 positions the flue damper 37 on the main flue 33 side, narrows the main flue 33, and bypasses the smoke. Expand the road 35. As a result, the amount of combustion gas passing through the bypass flue 35 increases and the amount of heat given to the saturated steam by the superheater 41 increases, so that the superheat temperature is increased.
On the other hand, when the superheated steam temperature is higher than the predetermined value, the superheat temperature controller 131 causes the flue damper 131 to fall to the bypass flue 35 side and reduces the amount of combustion gas passing through the bypass flue 37.

Next, the fuel supply system 133 will be described with reference to FIG.
The fuel supply system 133 includes a storage tank 135, a fuel oil supply line 137 that supplies fuel oil, for example, residual oil, to the main engine 9, and a liquid fuel supply line 139 that supplies liquid fuel, for example, residual oil, to the boiler 17. Is provided.
The fuel oil supply line 137 temporarily stores residual oil sent from the storage tank 135 by the first supply pump 141 to precipitate and separate heavy materials such as sludge, and residual oil from the residual oil. A centrifuge (separation means) 145 for separating heavy objects, a service tank 147 for storing residual oil from the centrifuge 145, and a residual oil from the engine supernatant tank 143 to the service tank 147 via the centrifuge 145 , A fine mesh filter (separating means) 151 for removing condensate containing sludge from the residual oil from the service tank 147, and supply the residual oil in the service tank 147 to the fine mesh filter 151. Residue that has passed through the third supply pump 153 and the fine mesh filter 151 The is provided with a fourth supply pump 155 supplies the main machine 9.

Further, the fuel supply line 137 is provided with a atomization device 157 that crushes and atomizes heavy materials such as sludge separated by the centrifugal separator 145. The fine particles containing the oil atomized by the atomizing device 157 are configured to be supplied to the liquid fuel supply line 139.
Further, the condensate containing the remaining sludge separated by the fine mesh filter 151 is also supplied to the liquid fuel supply line 139.
The liquid fuel supply line 139 includes a boiler clarification tank 159 for temporarily storing residual oil sent from the storage tank 135 by the first supply pump 141 to precipitate and separate heavy materials such as sludge, and a boiler clarification tank 157. A fifth supply pump 161 is provided that mixes the residual oil, the fine particles from the atomizer 157 and the separated product from the fine mesh filter 151 and supplies the mixed oil to the combustion device 26 of the boiler 17.

Operation | movement of the propulsion system of the ship 1 concerning this embodiment demonstrated above is demonstrated.
The marine vessel 1 is propelled by the rotation of the main propeller 5 driven mainly by the main engine 9 and is caused to sail.
When the propulsive force by the main propeller 5 is insufficient or when the attitude of the ship 1 is adjusted, the pod propeller 13 driven by the pod motor 15 is rotated, thereby covering the lack of propulsive force or the ship 1 The posture is adjusted (including steering).
Accordingly, the main propeller 5 and the pod propeller 13 may be driven simultaneously or individually. For example, the pod propeller 13 may be operated alone at a low speed such as in a harbor where maneuverability is required.

Next, for example, the operation of the propulsion system 3 will be described in the case where the ship 1 sails offshore and the main propeller 5 and the pod propeller 13 are driven together.
The main machine 9 generates power by burning the fuel oil supplied by the fuel supply line 137, and drives the main propeller 5 to rotate through the propeller shaft.
At this time, the exhaust gas after combustion of the fuel oil is discharged out of the ship through the exhaust gas passage 53, so that a considerable portion of the heat quantity of the fuel is discarded. The thermal efficiency of the two-stroke diesel engine (the ratio of the amount of heat the fuel uses as power) is as high as about 40%, but more than half of the amount of heat is still discarded as exhaust gas or cooling water.
On the other hand, the pod motor 15 is driven by electric power supplied from the generator 21 to drive the pod propeller 13 to rotate. The amount of power required for the generator 21 including the power at this time is 5 to 6000 kW in the case of a large ship.

The operation of the generator driving turbine 19 that generates rotational power converted into electric power by the generator 21 will be described.
In the boiler 17, the combustion device 26 burns the fuel supplied from the liquid fuel supply line 139 to generate combustion gas in the furnace 24. The combustion gas flows substantially horizontally from the furnace 24 to the main flue 33 and exchanges heat with water flowing in the lower half of the evaporator tube group 27.
Thereafter, the flow direction of the combustion gas is changed upward, and the combustion gas is separated into a gas that rises as it is through the bypass flue 35 and a gas that flows through the main flue 33 through heat exchange with the upper half of the evaporator tube group, and is downstream. Rejoin at the side and discharged out of the ship.

At this time, the fuel supplied from the liquid fuel supply line 139 contains waste oil separated by the fuel supply line 137. This is because the combustion device 26 of the boiler 17 can tolerate a relatively large amount of sludge.
Thus, since the waste oil part isolate | separated from the fuel supply line 137 which sends a fuel to the main engine 9 can be utilized as a fuel of the boiler 19, the energy of a fuel can be utilized effectively.
Further, even if the amount of waste oil in the fuel supply line 137 is increased, the waste oil rate as the propulsion system 3 does not increase. Therefore, the cleanliness in the centrifugal separator 145 and the fine mesh filter 151 is improved, and clean fuel is supplied to the main engine 9. Can be supplied. Thereby, in the main machine 9, problems such as wear can be reduced and the life can be improved. In addition, an inexpensive fuel such as residual oil can be used effectively.

The water supplied through the water supply line 87 by the water supply pump 93 is heated by the economizer 43 and introduced into the steam drum 29. The water supplied to the steam drum 29 is heated from the combustion gas while descending to the water drum 31 through the evaporator tube group 27 and is converted into high-pressure saturated steam (boiler pressure steam). The boiler pressure steam is collected in the steam drum 29 and supplied as a heat source from a boiler pressure steam line 65 to a necessary place in the ship. The steam is used in the ship and then returned to the atmospheric pressure condenser 73 through a line (not shown).
A part of the boiler pressure steam supplied from the boiler pressure steam line 65 is supplied to the superheater 41. The superheated steam superheated by the superheater 41 is introduced into the inlet of the generator driving turbine 19 through the superheated steam line 67.

Water is supplied to the high-pressure steam separator 47 from a water supply line 87. This water is sent to the high-pressure evaporator 45 through the high-pressure circulation line 49 by the high-pressure circulation pump 51, recovering the amount of heat from the exhaust gas passing through the high-pressure core 44, and becoming high-pressure saturated steam (high-pressure steam). The high-pressure steam returns to the high-pressure steam-water separator 47 through the high-pressure circulation line 49, is separated from water, and is stored in the upper part thereof.
The high-pressure steam is introduced into an air-fuel mixture stage at an intermediate position M of the generator driving turbine 19 through a high-pressure steam line 69.

Water is supplied to the low-pressure steam-water separator 59 through a water supply line 87. This water is sent to the low-pressure evaporator 57 through the low-pressure circulation line 61 by the low-pressure circulation pump 63, recovers the amount of heat from the exhaust gas passing through the low-pressure core 46, and becomes low-pressure saturated steam (low-pressure steam). The low-pressure steam returns to the low-pressure steam separator 59 through the low-pressure circulation line 61, is separated from water, and is stored in the upper part thereof.
This low-pressure steam is introduced into an air-fuel mixture stage at an intermediate position L of the generator driving turbine 19 through a low-pressure steam line 71.
The low-pressure steam is supplied as a heat source from a low-pressure steam supply line 81 to a necessary place in the ship. The steam is used in the ship and then returned to the atmospheric pressure condenser 73 through a line (not shown).

Since the heat recovery by the high pressure evaporator 45 and the low pressure evaporator 57 in the high pressure core 44 and the low pressure core 46 is performed with saturated steam, the pressure in the high pressure evaporator 45 and the low pressure evaporator 57, in other words, the high pressure steam generation means 23. The amount of steam can be adjusted by adjusting the pressure in the low-pressure steam generating means 25.
That is, when the pressure in the low-pressure evaporator 57 is increased, the amount of low-pressure steam decreases, and when the pressure is decreased, the amount of low-pressure steam increases. Further, when the pressure in the high-pressure evaporator 45 is increased, the amount of high-pressure steam decreases, but the amount of low-pressure steam increases. When the pressure in the high-pressure evaporator 45 is decreased, the amount of high-pressure steam increases, but the amount of low-pressure steam decreases.

As the pressure in the low-pressure evaporator 57 is reduced, the amount of heat recovered from the exhaust gas increases, but the temperature of the exhaust gas decreases accordingly. When the temperature of the exhaust gas is lowered, condensation of acidic components contained in the exhaust gas proceeds and corrosion caused thereby is promoted. Therefore, it is preferable to maintain the pressure in the low-pressure evaporator 57 at a constant pressure that is not so low. It is.
When the low-pressure dump valve 107 is opened, the low-pressure steam in the low-pressure steam line 71 is discharged to the atmospheric pressure condenser 73, so that the pressure in the low-pressure steam generation means 25 decreases. On the other hand, when the low-pressure steam supply valve 105 is opened, the high-pressure steam in the high-pressure steam line 69 flows into the low-pressure steam / water separator 59 via the communication line 83, so that the pressure in the high-pressure steam generating means 23 decreases, and the low-pressure steam The pressure in the production | generation means 25 increases.
The pressure in the high-pressure evaporator 45 and the low-pressure evaporator 57 can be adjusted by appropriately adjusting the opening degrees of the low-pressure steam supply valve 105 and the low-pressure dump valve 107.

In the generator driving turbine 19, the kinetic energy generated by the expansion of the introduced superheated steam, high-pressure steam and low-pressure steam is converted into rotational power, and the generator 21 is rotationally driven by this rotational power to generate electric power.
The electric power generated by the generator 21 is sent to the pod motor 15 to drive the pod motor 15 and rotate the pod propeller 13.
Moreover, the electric power generated by the generator 21 is transmitted to a required place in the ship.

The steam that has driven the generator driving turbine 19 is collected in the suction condenser 85, condensed, and returned to the water.
The water in the suction condenser 85 is sent to the low-pressure steam / water separator 59 via the water supply line 87 by the suction condenser pump 91 and the water in the atmospheric condenser 73 by the atmospheric condenser pump 89.
And this water is warmed by the heat | fever collect | recovered from the waste gas of the main engine 9 with the low pressure steam-water separator 59, and the contained gas component is isolate | separated. That is, the low-pressure steam-water separator 59 fulfills the function of a dilator normally provided in the water supply line of the boiler 17.
The gas components are separated and the preheated water is sent to the steam drum 29 by the feed water pump 93.
Thus, since the low-pressure steam-water separator 59 separates the gas and preheats it, it is not necessary to provide a separate dialator in the water supply line 87, and it can be manufactured inexpensively.

  In this way, the generator driving turbine 19 that drives the generator 21 that supplies power to the pod motor 15 that rotates the pod propeller 13, in addition to the superheated steam generated by the boiler 17, Since it is also driven by high-pressure steam and low-pressure steam generated as heat sources, the amount of heat discarded from the main engine 9 can be fully utilized, and the energy efficiency of the propulsion system 3 can be improved.

Next, the steam amount adjustment of the superheated steam line 67, the high pressure steam line 69, and the low pressure steam line 71 will be described.
The amount and temperature of the exhaust gas of the main machine 9 fluctuate in accordance with the operation status of the main machine 9. Corresponding to this variation, the amount of high-pressure steam and low-pressure steam generated by recovering heat from the exhaust gas varies.
In the generator driving turbine 19, when the maximum power is exhibited, the amount of steam used for power conversion in each stage is limited. In other words, the amount of steam at the outlet at this time is substantially constant. That is, for example, when the amount of superheated steam is large, only a small amount of high-pressure steam and low-pressure steam is introduced. On the contrary, if a large amount of high-pressure steam and low-pressure steam is introduced, the amount of superheated steam can be reduced.

For example, when the amount of high-pressure steam generated by the high-pressure steam generation means 23 increases, the amount of steam sent to the high-pressure steam line 69 increases. However, since the amount of high-pressure steam introduced into the generator driving turbine 19 is limited, the amount of high-pressure steam remaining in the high-pressure steam line 69 increases.
When the high-pressure steam staying in the high-pressure steam line 69 increases, the pressure in the high-pressure steam line 69, the communication line 83, and the steam supply line 77 increases.
The high pressure gauge 115 measures this pressure, but no action is taken against the increase in pressure. When the pressure in the high-pressure steam line 69 increases, the pressure difference from the low-pressure steam increases, so the amount of high-pressure steam flowing into the low-pressure steam / water separator 59 through the low-pressure steam supply valve 105 increases.
As a result, the amount of steam in the high-pressure steam line 69 decreases and the pressure also decreases.
Along with this, the amount of low-pressure steam generated in the low-pressure steam generating means 23 increases. In this case, the pressure of the low-pressure steam line 71 described later is adjusted.

And when the pressure in the high pressure steam line 69 falls below a predetermined value, this indicates that the high pressure steam is insufficient. In this case, the high pressure controller 113 opens the high pressure steam supply valve 103 to supply the boiler pressure steam of the boiler pressure steam line 65 to the high pressure steam line 69.
When the high-pressure steam supply valve 103 is opened, the signal is sent to the governor 119. The governor 119 corrects the instruction command D based on this signal so that the opening degree of the main steam valve 117 increases. Based on this corrected instruction command D, the opening of the main steam valve 117 is opened.
When the opening degree of the main steam valve 117 is opened, the amount of steam that can be introduced from the intermediate positions M and L decreases, so that the amount of high-pressure steam introduced from the high-pressure steam line 69 to the generator driving turbine 19 decreases.
As a result, the amount of high-pressure steam staying in the high-pressure steam line 69 increases and the pressure in the high-pressure steam line 69 increases. When the pressure in the high pressure steam line 69 increases, the high pressure steam supply valve 103 is closed.
The predetermined pressure value at which the high-pressure steam supply valve 103 is opened varies depending on the exhaust gas temperature, but is higher than the planned pressure of the mixture stage at the position M in at least the entire operation range of the generator driving turbine 19. Is set to

Next, the low pressure steam will be described.
When the amount of low-pressure steam generated in the low-pressure steam generating means 25 increases due to an increase in the amount of inflow of high-pressure steam or an increase in the amount of exhaust gas, the amount of steam sent to the low-pressure steam line 71 increases. However, since the amount of low-pressure steam introduced into the generator driving turbine 19 is limited, the amount of low-pressure steam staying in the low-pressure steam line 71 increases.
When the low-pressure steam staying in the low-pressure steam line 71 increases, the pressure in the low-pressure steam line 71 and the low-pressure steam supply line 81 communicated therewith increases.
This pressure is measured by the low-pressure pressure gauge 111. When the pressure increases, the low-pressure controller 109 increases the opening of the low-pressure dump valve 107 as shown in FIG. Is sent to the atmospheric pressure condenser 73.
As a result, the amount of low-pressure steam that stays in the low-pressure steam line 71 decreases, so the pressure in the low-pressure steam line 71 decreases. When the pressure in the low-pressure steam line 71 decreases, the opening degree of the low-pressure dump valve 107 is reduced.

High pressure steam is supplied to the low pressure steam separator 59 via the low pressure steam supply valve 105. This high-pressure steam is a steam source and a heating source in the low-pressure steam generation means 25. If there is a large amount of this high-pressure steam, the amount of low-pressure steam generated increases, so that no matter how much the low-pressure dump valve 107 is opened, it stays in the low-pressure steam line 71. The pressure in the low-pressure steam line 71 may increase without the low-pressure steam decreasing.
In this case, as shown in FIG. 4, the low pressure controller 109 restricts the opening of the low pressure steam supply valve 105, restricts the amount of high pressure steam flowing into the low pressure steam separator 59, and reduces the amount of low pressure steam generated. Try to suppress.
When the pressure in the low-pressure steam line 71 decreases, the pressure difference from the high-pressure steam increases, so the amount of high-pressure steam flowing from the low-pressure steam supply valve 105 to the low-pressure steam-water separator increases. As a result, the amount of low-pressure steam generated increases and the pressure in the low-pressure steam line 71 increases.
In this way, the pressure of the low-pressure steam line 71 is adjusted.

On the other hand, when the opening degree of the low pressure dump valve 107 increases, the signal is sent to the governor 119. The governor 119 corrects the instruction command D based on this signal so that the opening degree of the main steam valve 117 decreases. Based on the corrected instruction command D, the main steam valve 117 is throttled.
When the main steam valve 117 is throttled, the amount of steam that can be introduced from the intermediate positions M and L increases, so the amount of low-pressure steam introduced from the low-pressure steam line 71 to the generator driving turbine 19 increases.
As a result, the amount of low-pressure steam staying in the low-pressure steam line 71 is reduced, and the pressure in the low-pressure steam line 71 is reduced. When the pressure in the low-pressure steam line 71 decreases, the opening degree of the low-pressure dump valve 107 is reduced, and a large amount of low-pressure steam that is not operated is not discharged to the atmospheric pressure condenser 73.

Thus, in this embodiment, when the amount of steam in the high-pressure steam line 69 and the low-pressure steam line 71 increases or decreases, the superheated steam supply amount in the superheated steam line 67 is adjusted to decrease on the contrary. It is used preferentially in the generator drive turbine 19.
As a result, the high-pressure steam and low-pressure steam generated by recovering the amount of heat from the exhaust gas of the main engine 9 are effectively utilized by the generator driving turbine 19 even if the amount of steam increases or decreases in accordance with the operating status of the main engine 9 and the like. Thus, the energy efficiency of the propulsion system can be further improved.

Further, the amount of superheated steam supplied to the generator driving turbine 19 varies according to the variation of the high pressure steam amount and the low pressure steam amount. For this reason, since the amount of steam per unit time passing through the superheater 41 varies, the superheated steam temperature varies when a certain combustion gas passes.
In the present embodiment, the superheat temperature controller 131 adjusts the position of the flue damper 37 according to the superheated steam temperature measured by the superheat thermometer 129 and adjusts the amount of combustion gas passing through the bypass flue 35. Yes. For this reason, even if the superheated steam flow rate of the superheated steam line 67 fluctuates, it is possible to keep the superheated steam temperature within a predetermined range.

  In a harbor or the like, when cruising at low speed and maneuverability are required, only the pod propulsion unit 7 is sometimes operated. In this case, since the main machine 9 is stopped, no exhaust gas exists. For this reason, since high pressure steam and low pressure steam are not generated, the high pressure on / off valve 123 and the low pressure on / off valve 127 are closed. The generator driving turbine 19 is driven by superheated steam generated by the boiler.

When applied to an LNG ship as the ship 1, the combustion device 26 of the boiler 17 is an oil / gas mixed combustion type, and is connected to a gas supply line 163 that supplies natural gas to the combustion device 26. In this way, surplus boil-off gas can be utilized as fuel for the boiler 17, and therefore, for example, it is not possible to dispose of them without being treated.
For this reason, for example, when a boil-off gas reliquefaction device is provided, it becomes an effective processing means for boil-off gas when the liquefaction device is not in operation, and the rated liquefaction capacity of the liquefaction device itself is temporarily increased. Since it can be determined according to the amount of boil-off gas that is constantly generated without consideration, it is economical in terms of initial investment and liquefaction efficiency.
Further, a steam turbine device using high-pressure steam and low-pressure steam can be used as a drive unit for a reliquefaction device, for example, a refrigerant circulation cycle.

In this embodiment, it is the ship 1 provided with the propulsion system 3 which combined the main engine 9 of the diesel engine and the pod propulsion unit 7 of the electric propulsion, but the present invention is not limited to this, and is illustrated in FIG. The present invention can be applied to a ship having a propulsion system as described above.
FIG. 5A shows an in-line propulsion system in which the electric motor 4 is attached to the shaft extension of the main machine 9.
FIG. 5B shows a PTO (Power Take Off) type propulsion system, in which the electric motor 4 is configured to drive the shaft of the main unit 9 via a gear 6.
FIG. 5C is provided with a thruster 8 driven by the motor 4.
FIG. 5D shows a CRP (Contra Rotation Propeller) type propulsion system. The auxiliary propeller shaft centered on the coaxial line is provided outside the propeller shaft of the main machine 9, and the auxiliary propeller 10 is attached to the main propeller 5 so as to face the main propeller 5, and the electric motor 4 mainly attaches the auxiliary propeller 10 via the gear 6. The propeller 5 is rotated in the opposite direction.
FIG. 5E shows a shaft generator type propulsion system in which an electric motor 4 is provided on a shaft connecting the main engine 9 and the main propeller 5.

1 is a block diagram showing an overall schematic configuration of a propulsion system according to an embodiment of the present invention. It is a block diagram showing a schematic structure of a fuel supply system concerning one embodiment of the present invention. It is a block diagram which shows the control flow of the steam valve used for the propulsion system concerning one Embodiment of this invention. It is a graph which shows the relationship between the pressure and opening degree of a low pressure dump valve and a high pressure dump valve. 1 is a block diagram illustrating a propulsion system to which the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ship 3 Propulsion system 7 Pod propulsion device 9 Main engine 17 Boiler 19 Generator drive turbine 21 Generator 23 High pressure steam generation means 25 Low pressure steam generation means 29 Steam drum 33 Main flue 35 Bypass flue 37 Flue damper 45 High pressure evaporation High pressure steam / water separator 49 High pressure circulation line 53 Exhaust gas passage 57 Low pressure evaporator 59 Low pressure steam / water separator 61 Low pressure circulation line 67 Superheated steam supply line 69 High pressure steam line 71 Low pressure steam line 87 Water supply line 103 High pressure steam supply valve 105 Low pressure steam supply valve 107 Low pressure dump valve 117 Main steam valve 119 Governor 137 Fuel oil supply line 139 Liquid fuel supply line 145 Centrifugal separator 151 Fine mesh filter

Claims (6)

In a ship internal combustion engine waste heat recovery plant having a propulsion system that combines a main engine and electric propulsion by an internal combustion engine,
Driving a generator for supplying electric power for electric propulsion, and a generator driving turbine having a plurality of mixed air stages in an intermediate portion;
A boiler that produces saturated steam and superheated steam;
High-pressure steam generating means for recovering heat from the exhaust gas of the internal combustion engine to generate high-pressure steam;
Low pressure steam generating means for recovering heat from the exhaust gas of the internal combustion engine to generate low pressure steam downstream of the high pressure steam generating means;
A superheated steam supply line for introducing superheated steam generated by the boiler into an inlet of the generator driving turbine;
A high-pressure steam line for introducing the high-pressure steam generated by the high-pressure steam generating means into the upper mixed gas stage of the generator driving turbine;
A low-pressure steam line for introducing the low-pressure steam generated by the low-pressure steam generating means into the lower mixed stage of the generator driving turbine;
Control means for adjusting the supply amount of the superheated steam line to be decreased on the contrary when the amount of steam in the high pressure steam line and the low pressure steam line increases or decreases;
An internal combustion engine waste heat recovery plant for ships. The high-pressure steam generating means connects a high-pressure evaporator installed in an exhaust gas passage of an internal combustion engine, a high-pressure steam / water separator that supplies water and separates the high-pressure steam, and the high-pressure evaporator and the high-pressure steam / water separator. And a high-pressure circulation line for circulating the fluid,
The low-pressure steam generating means includes a low-pressure evaporator installed on the downstream side of the high-pressure evaporator in an exhaust gas passage of an internal combustion engine, a low-pressure steam separator that supplies water and separates low-pressure steam, the low-pressure evaporator, A low-pressure circulation line for circulating the fluid by connecting the low-pressure steam separator,
2. The internal combustion engine waste heat recovery plant for a ship according to claim 1, wherein the low-pressure steam separator is installed in a water supply line to a boiler. The high-pressure steam generating means connects a high-pressure evaporator installed in an exhaust gas passage of an internal combustion engine, a high-pressure steam / water separator that supplies water and separates the high-pressure steam, and the high-pressure evaporator and the high-pressure steam / water separator. And a high-pressure circulation line for circulating the fluid,
The low-pressure steam generating means includes a low-pressure evaporator installed on the downstream side of the high-pressure evaporator in an exhaust gas passage of an internal combustion engine, a low-pressure steam separator that supplies water and separates low-pressure steam, the low-pressure evaporator, A low-pressure circulation line for circulating the fluid by connecting the low-pressure steam separator,
3. The ship internal combustion engine waste heat recovery plant according to claim 1, wherein the high-pressure steam separator is a steam drum of the boiler.   The boiler includes a bypass flue that branches off from the main flue and does not pass through a part of the water pipe, a superheater installed in the bypass flue, and a combustion gas that passes through the main flue and the bypass flue 4. The internal combustion engine waste heat recovery plant for a ship according to claim 1, further comprising: a flow path adjusting unit that adjusts the ratio of The fuel oil supply line of the internal combustion engine is provided with a separating means for separating the solid content from the liquid fuel containing the solid content,
5. The waste oil component separated from the liquid fuel by the separation means is configured to be supplied to a liquid fuel supply line of the boiler. Ship internal combustion engine waste heat recovery plant. A ship comprising the internal combustion engine waste heat recovery plant according to any one of claims 1 to 5.

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